1. Technical Field of the Invention
The invention relates to a storage and retrieval unit for storing and removing from store containers or pallets belonging to a rack, having at least one endless drive element which is led around two wheels arranged at a distance from each other and has an upper run and a lower run and on which at least one gripping means for gripping a container or a pallet is arranged.
2. Prior Art
Storage and retrieval units of this type are known for picking up and depositing loads in racks. The storage and retrieval unit is arranged on a vehicle which, for example, can be moved horizontally and vertically on rails between racks. Using the storage and retrieval unit, containers or pallets are loaded onto the vehicle and put into store from the vehicle at the envisaged storage space in the rack. Important in such storage and retrieval units are a high throughput, a low demand for space and the greatest possible precision when picking up and depositing the containers or pallets.
A storage and retrieval unit of the aforementioned type has been disclosed by WO 01/10751 from the applicant. This has gripping arms which are inclined with respect to the pulling direction of the endless drive element and which each have a cam which moves into a vertical groove in the pallet in order to grip a container or a pallet. As a container or a pallet is gripped, the cam moves into the groove from below. As the container or the pallet is deposited, the cam moves upward out of the groove again. In practice, the storage and retrieval unit has proven to be extremely worthwhile. For this storage and retrieval unit, an appropriate container or a pallet which has the aforementioned appropriate adapted groove is necessary. Previously usual containers cannot generally be used here.
EP-A-0 322 313 discloses a storage and retrieval unit in which a gripping means is likewise provided which, at an outer end, has a cam which moves into a groove in a container. Commercially available containers or pallets cannot be used in this storage and retrieval unit either. This is likewise true of the storage and retrieval unit according to DE-A-195 01 893. DE-A-42 33 690 discloses a storage and retrieval unit in which, in order to grip a container, a gripper engages fully in a groove in the container. This storage and retrieval unit can only be moved vertically between stored containers, since it would collide with the containers in the event of a horizontal movement. In addition, this storage and retrieval unit also requires a specific container.